An artificial heart may be used for a heart patient if a surgeon determines that the actual heart of the patient cannot operate normally and thereby cannot maintain the blood pumping function. Conventional artificial hearts are classified into two types, which are total artificial hearts (TAH) and ventricular assist devices (VAD), according to the original intended function of the heart and the actual function of the heart in the body of a patient. The TAH is implanted in the body of a patient after the human heart has been removed from the body, so that the TAH must execute the heart's function in place of the removed human heart. However, the VAD is implanted in the body of a patient without removing the human heart from the body, and assists the function of the left or right ventricle.
Conventional VADs are classified into two types, which are intracorporeal VADs and extracorporeal VADs, according to the location of a VAD relative to the body of a patient. Because the TAH completely replaces the human heart of a patient, that is, occupies the physical space and provides the entire functionality of the human heart, the TAH requires a donor, thereby causing several problems. However, the VAD, which is used in conjunction with the human heart without removing the human heart from a patient, comprises an artificial blood pump connected to the ventricles of the human heart and to the artery of the patient through blood conduits, thus feeding blood from an inlet to an outlet of the pump to discharge the blood to the artery. Unlike the TAHs, the VADs replace only some of the functionality of the human heart.
The VAD uses an artificial blood pump to assist the blood pumping function of the human heart to efficiently pump the blood required by the body of a patient as long as some of the functionality of the human heart is maintained. When surgeons determine that the functioning of the human heart of the patient using the artificial blood pump of the VAD has improved and the human heart can execute its normal functions, the blood pump of the VAD may be disconnected from the patient so that the patient may live normally.
The blood pumps are classified into a pulsatile blood pump and a non-pulsatile blood pump according to the blood current generation manner of the blood pump. The pulsatile blood pump is configured such that, when a blood bag or a blood containing part functioning as an artificial ventricle is compressed, the pump discharges blood under pressure. The non-pulsatile blood pump is configured such that an impeller, which is in direct contact with blood, is rotated at a high speed and generates a rotating force to pump blood out.
The conventional pulsatile blood pump is used with a pump actuating device to cause variation in pressure in an artificial ventricle. The conventional actuating devices for pulsatile blood pumps are classified into a pneumatic device to compress a blood sac or diaphragm using compressed air and a mechanical device to mechanically compress a blood sac or diaphragm using a mechanical mechanism. The pneumatic actuating device for pulsatile blood pumps connects compressed air, prepared in a hospital, compresses a blood bag of the pump using the compressed air and restores the blood bag using a vacuum. Furthermore, a mobile actuating device for pulsatile blood pumps, which has both a vacuum pump and an air compressor and is connected to an artificial ventricle, has been proposed and used. However, the conventional mobile actuating device having a vacuum pump and an air compressor is problematic in that the device has a large size and a heavy weight so that the device is not easy to use in a place other than hospitals, thus restricting the movement of a patient.